Spring-loaded clamps



April 25, 1961 c. G. HEFFORD SPRING-LOADED CLAMPS Filed Dec. 16, 1957United States Patent Stadium Limited, Enfield, Middlesex, England, aBritish company Filed Dec. 16, 1957, Ser. No. 702,927

2 Claims. 7 (Cl. 24-253) Inspection lamps and other devices may bemounted on clamps which can be closed onto a convenient member to holdthe device temporarily in a desired position. One form of clamp for thispurpose consists of two arms pivoted together and having opposed jaws atone end and handles at the other end. A spring acts on the arms to urgethe jaws together.

There is a definite upper limit imposed on the range of sizes of memberwhich the jaws will grip, owing to the fact that the range of travel ofthe handles and the strength of the spring are limited by the size andstrength of a users hand, while the mechanic-a1 advantage between thehandles and the jaws is limited by the magnitude of the force which thejaws must exert on the member if they are not to slip when the handlesare released.

According to the present invention, in such a clamp one at least of thejaws is adjustable in position towards and away from the other jaw whilethe handles remain in the same relative position. The adjustment neednot be progressive and need not be such that it can be made while thejaws are in contact with -a member. pose of the adjustment is to providetwo or more alternative ranges of relative movement of the jaws, ofsubstantially the same extent but with difierent maximum and minimumvalues. It is of course convenient for the ranges to overlap somewhat.Thus the total range of sizes ofrmember which the jaws will grip isincreased in comparison with clamps in which no adjustment is possible.

Preferably only one jaw is adjustable, and the adjustment is provided bypivoting the jaw on the same pivot as the two arms, and connecting thejaw to its arm by an adjustable link.

The pur-' 2,980,977. Patented Apr. 25, 1961 with the handle 8. The jaw 6is independently pivoted on the pin 2 and is connected to the handle 10by a hasp 12. This hasp has two alternative notches 14 and 15 which canengage a pin 16 on the handle 10. To permit the necessary movementduring adjustment the hasp is pivoted to the jaw 6 on a stud 18 andincludes a hinge 20.

An inspection lamp 22 is pivotally mounted in a fork 24, which is inturn pivoted to the base of the jaw 4 on a stud 26. o

The two jaws are urged together by the action of a spring 28 which iscoiled about the pin 2 and acts on the handles 8 and 10.

Figure 3 shows the different ranges of the movement of the clamp. Whenthe notch 14 is engaging the pin 16, as shown in Figure 1, then thehandle 10 is movable between the position 10a and 1012 while the jaw 6is movable between the position 6a and- 61). When the notch 15 is inengagement with the pin 16, as shown in Figure 2, then the handle 10 ismovable between the position 100 and 10b and the jaw 6 is movablebetween the position 66 and 6d. It will be seen that the range ofmovement of the handle 10 is such that the two handles can be controlledby one hand while the two alternative ranges of move- For example, thelink may be a hasppivoted to the jaw and having several notches whichcan alternatively engage a pin on the arm. If the pivot axis of the haspis not parallel to the pivot axis of the arms and jaw, then the haspshould be hinged.

As another example the jaw may have a slotted quadrant co-operating witha lockingsore'w on the arm.

The accompanying drawings show one example of an inspection lamp mountedon a clamp according to the present invention.

In these drawings:

V Figure 1 is a perspective view showing the clamp closed with theadjustable jaw in one position;

Figure 2 is a fragmentary perspective view showing the clamp closed withthe adjustable jaw in another position; and

Figure 3 is a diagram showing the ranges of movement of the adjustablejaw.

handles 8 and 10 at-the other-end. The jaw 4 is integral m'ent of thejaw 6 overlap. I

I claim:

1. A clamp comprising two arms pivoted together, each of said armshaving a handle at one end and a jaw at the other end, said handlesbeing opposed to one another, a spring acting on said arms to urge saidjaws toward one another, the jaw of one at said arms being pivoted tothe handle of said one arm and said one arm having means for securingits jaw rigidly at any one of a plurality of angular positions withrespect to said handle of said one arm, and in which said securing meanscomprises a pin on the handle of said one arm and a hasp, said haspbeing pivoted to said jaw of said one arm and including a hinge andbeing formed with two notches therein whereby said movable jaw can besecured in either of two angular positions with respect to said handleby the engagement of said pin in alternative notches in said hasp.

2. A clamp comprising two arms pivoted together, each of said armshaving a handle at one end and a jaw at the other end, said handlesbeing opposed to one another, a spring acting on said arms to urge saidjaws toward one another, the jaw of one of said arms being pivoted tothe handle of said one arm, and said one am having means for securingits jaw rigidly at any one of a plurality of angular positions withrespect to said handle of one arm, and in which said pivoted jaw of saidone arm is pivoted to the said handle of said one arm about the sameaxis as said two arms are pivoted to one another.

References Cited in the file of this patent UNITED STATES PATENTS GreatBritain Apr. 1 0, 1957 i

